The Lib Dem leader's tougher words on immigration policy today reveal the lack of "wisdom" from his advisers during his debates with Ukip's Nigel Farage.

Nick Clegg is to make a speech on immigration today, which revises his position. Photo: Getty

Two politicians decide to have a debate.

One – let’s call him Nigel – adopts the position “Black”

The other – Nick – holds the position “White”.

Except it’s not pure brilliant white. It’s more whitie-sh. Indeed, he thinks there are bits of black that are worth considering and adding to the white. So his position is more, well, grey. But definitely the whiter end of the grey spectrum.

So Nick doesn’t go into the debate and argue what he thinks. He argues that white is best, white must prevail, there is no room for compromise. Indeed, when asked what the white will look like in 10 years time, Nick doesn’t say “grey”. Nick says “I suspect it’ll be quite similar to what it is now”.

Nick loses the debate. Which, fine debater though he is, is not surprising, given he wasn’t actually arguing for what he believed in. He was just trying to look like the opposite to Nigel. And Nigel’s more popular than Nick.

Of course, the mistake was listening to the received wisdom in the first place –that you have to take a pure, unadulterated position against a conviction politician. Tonight’s Scottish independence debate will see one side take the position “Yes” and the other, “No – but we could be a bit more independent than we currently are couldn’t we, with a few more tax and spend powers?” And strangely enough, the good people of Scotland seem to be coping with this nuanced position just fine, thank you very much.

And now, Nick’s got even more of a problem. He already has a bit of a reputation for not following through on his pledges. Today he’s going to make a speech on immigration, especially immigration in the EU, in which – if his email to members is anything to go by – will make plain his more nuanced position.

Freedom of movement between EU member states is a good thing. However - and I say this as a pro-European - it was always intended as a right to work, not a right to claim benefits. So we're returning freedom of movement to it's original intention and I believe that when the EU enlarges in the future we'll also need to be stricter on the transition controls we apply to new member states. This isn't about bolting the door; it's about managing the flow of migrants into the country in a way that is sustainable and fair.

He clearly hopes this will be interpreted as showing that, in contrast to anything you thought previously, he is firmly in the grey camp. Indeed, maybe a bit of a darker grey than he’s let on previously. He’s not in the Pure Brilliant White camp at all, deary me no. How could you have drawn that conclusion?

And everyone’s going to answer: “because you adopted the position ‘white’ in two national debates not three months ago”.